1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * https://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19 package org.apache.bcel.classfile;
20
21 import java.io.DataInput;
22 import java.io.DataOutputStream;
23 import java.io.IOException;
24
25 import org.apache.bcel.Const;
26
27 /**
28 * This class is derived from the abstract {@link Constant} and represents a reference to a method handle.
29 *
30 * @see Constant
31 * @since 6.0
32 */
33 public final class ConstantMethodHandle extends Constant {
34
35 private int referenceKind;
36 private int referenceIndex;
37
38 /**
39 * Initialize from another object.
40 *
41 * @param c Source to copy.
42 */
43 public ConstantMethodHandle(final ConstantMethodHandle c) {
44 this(c.getReferenceKind(), c.getReferenceIndex());
45 }
46
47 /**
48 * Initialize instance from file data.
49 *
50 * @param file Input stream.
51 * @throws IOException if an I/O error occurs.
52 */
53 ConstantMethodHandle(final DataInput file) throws IOException {
54 this(file.readUnsignedByte(), file.readUnsignedShort());
55 }
56
57 /**
58 * Constructs a ConstantMethodHandle.
59 *
60 * @param referenceKind Kind of method reference.
61 * @param referenceIndex Index to the method reference.
62 */
63 public ConstantMethodHandle(final int referenceKind, final int referenceIndex) {
64 super(Const.CONSTANT_MethodHandle);
65 this.referenceKind = referenceKind;
66 this.referenceIndex = referenceIndex;
67 }
68
69 /**
70 * Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class. I.e.,
71 * the hierarchy of methods, fields, attributes, etc. spawns a tree of objects.
72 *
73 * @param v Visitor object.
74 */
75 @Override
76 public void accept(final Visitor v) {
77 v.visitConstantMethodHandle(this);
78 }
79
80 /**
81 * Dumps method kind and index to file stream in binary format.
82 *
83 * @param file Output file stream.
84 * @throws IOException if an I/O error occurs.
85 */
86 @Override
87 public void dump(final DataOutputStream file) throws IOException {
88 file.writeByte(super.getTag());
89 file.writeByte(referenceKind);
90 file.writeShort(referenceIndex);
91 }
92
93 /**
94 * Gets the reference index.
95 *
96 * @return the reference index.
97 */
98 public int getReferenceIndex() {
99 return referenceIndex;
100 }
101
102 /**
103 * Gets the reference kind.
104 *
105 * @return the reference kind.
106 */
107 public int getReferenceKind() {
108 return referenceKind;
109 }
110
111 /**
112 * Sets the reference index.
113 *
114 * @param referenceIndex the reference index.
115 */
116 public void setReferenceIndex(final int referenceIndex) {
117 this.referenceIndex = referenceIndex;
118 }
119
120 /**
121 * Sets the reference kind.
122 *
123 * @param referenceKind the reference kind.
124 */
125 public void setReferenceKind(final int referenceKind) {
126 this.referenceKind = referenceKind;
127 }
128
129 /**
130 * @return String representation.
131 */
132 @Override
133 public String toString() {
134 return super.toString() + "(referenceKind = " + referenceKind + ", referenceIndex = " + referenceIndex + ")";
135 }
136 }